1. Field of the Invention
The present invention relates to an improved controller for an iontophoretic drug delivery device, and more particularly relates to a controller having a number of features which improve usability and traceability of the iontophoretic drug delivery device.
2. Background of the Related Art
Iontophoresis may be defined as the introduction of medicaments by means of an electric current into the tissues of the body for therapeutic purposes. Iontophoretic devices, have, in recent years, become an increasingly important means of administering therapeutic agents. Such systems offer advantages clearly not achievable by any other methods of administration, such as by ingestion or by injection through the skin.
Presently, known iontophoretic devices use at least two electrodes, which are in contact with a portion of a patient's body. A first electrode, generally called the active electrode, delivers the ionic substance or drug into the body by iontophoresis. The second electrode, generally called the counter electrode, closes an electrical circuit that includes the first electrode and the patient's body. Generally, the circuit includes a source of electrical energy, such as a battery. The ionic substance to be driven into the body may be either positively charged or negatively charged. In the case of a positively charged ionic substance, the anode of the iontophoretic device becomes the active electrode and the cathode serves as the counter electrode to complete the circuit. Alternatively, if the ionic substance to be iontophoreticly delivered is negatively charged, the cathode will be the active electrode and the anode will be the counter electrode.
One type of iontophoretic drug delivery device includes a separate, reusable controller, which can be removably, electrically coupled to a patch containing the therapeutic agent. The controller includes the electronics which control the amount of current applied to the patch as well as the duration of the applied current. Delivery of a drug to the patient may be accomplished at a constant rate over a long period of time or, alternatively, at periodic intervals. Thus, it may be necessary for the drug-containing patch to be maintained in contact with the patient's skin for a long period of time, either for continuous drug delivery, or to permit frequent interval delivery over a period of time.
In situations where the periodic delivery of the medicament is indicated, there is no need to maintain the source of electric current connected to the patch between doses. While the unobtrusive medicament-containing patch may remain attached to the patient, removability of the current source would permit the patient to be free from cumbersome connection to the current source between doses. At such time as iontophoretic drug delivery is once again necessary, the medicament-containing patch attached to the patient's skin may be reconnected to the current source. Since the current source generally includes a battery, it would be helpful to know the number of times the controller has been used as well as the duration of the use. In this manner, one can ensure that the controller has sufficient energy to transdermally deliver the necessary dosage of medicament to the patient.
In situations where the iontophoretic device is applied by the patient himself, it would be helpful to health-care professionals to be able to determine if the patient has actually received the medication. For example, it would be beneficial if the controller could communicate with the health-care professional to provide proof that it has actually delivered the medication to the patient.
As previously noted, it may be necessary to use an iontophoretic drug delivery device over an extended period of time i.e., longer than 24 hours to delivery the necessary dosage of drug. As the length of delivery time increases, there is a need to develop small, unobtrusive iontophoretic delivery devices which can be easily worn on the skin under clothing.
In addition to the need for developing smaller iontophoretic devices, there is need to reduce the cost of these devices in order to make them more competitive with conventional forms of therapy such as pills and subcutaneous injections. One manner of improving cost effectiveness is to have a reusable controller which includes the costly electronics that provides the current to drive the patch.
It is an object of the present invention to provide an improved iontophoretic drug delivery device having a reusable controller which can record the number of times the controller has been used.
It is a further object of the present invention to provide an improved iontophoretic drug delivery device having a controller which includes a clock for timing a useful life of the controller.
It is still a further object of the present invention to provide an iontophoretic drug delivery device having a unique serial number embedded in the controller electronics for purposes of traceability and security.
It is yet a further object of the present invention to provide an iontophoretic drug delivery device having a controller which is capable of recording dates, times and/or duration of usage and provide the resulting information to a health-care professional to evaluate patient compliance in receiving prescribed medication.
It is yet a further object of the present invention to provide an improved iontophoretic drug delivery device having a controller which includes an LED indicator. The LED indicator is capable of sending information from the controller to a health-care professional. Additionally, the LED can act as a photo receiver to receive information to thereby instruct the controller.